Patient-centred measurement of recovery from day-case surgery using wrist worn accelerometers: a pilot and feasibility study*

This pilot and feasibility study evaluated wrist-worn accelerometers to measure recovery from day-case surgery in comparison with daily quality of recovery-15 scores. The protocol was designed with extensive patient and public involvement and engagement, and delivered by a research network of anaesthesia trainees. Forty-eight patients recruited through pre-operative assessment clinics wore wrist accelerometers for 7 days before (pre-operative) and immediately after elective surgery (early postoperative), and again at 3 months (late postoperative). Validated activity and quality of recovery questionnaires were administered. Raw accelerometry data were archived and analysed using open source software. The mean (SD) number of valid days of accelerometer wear per participant in the pre-operative, early and late postoperative periods were 5.4 (1.7), 6.6 (1.1) and 6.6 (1.0) days, respectively. On the day after surgery, Euclidian norm minus one (a summary measure of raw accelerations), step count, light physical activity and moderate/vigorous physical activity decreased to 57%, 47%, 59% and 35% of baseline values, respectively. Activity increased progressively on a daily basis but had not returned to baseline values by 7 days. Patient questionnaires suggested subjective recovery by postoperative day 3 to 4; however, accelerometry data showed that activity levels had not returned to baseline at this point. All activity measures had returned to baseline by 3 months. Wrist-worn accelerometery is acceptable to patients and feasible as a surrogate measure for monitoring postoperative recovery from day-case surgery. Our results suggest that patients may overestimate their rate of recovery from day-case surgery, which has important implications for future research.